The purpose of this study was to use the social networking site Facebook to explore the relationship between religion and sex in emerging adults. Public profiles were examined at four Time points during freshman year. One hundred fifty profiles were analyzed for self-displayed religious affiliation, references to religiosity, and references to sexual behavior. Analyses included mixed-effects logistic regression, mixed-effects Poisson regression, and nonparametric Kruskal-Wallis test. Displayed religious affiliation and references to sexual behavior decreased over the year. References to religiosity slightly increased. Across all Time points, displayers of religiosity had 65% fewer sexual references compared with non-displayers. Facebook is a venue to evaluate how emerging adults are displaying the relationship between religion and sex over time.